Venturi type safety device



May 11, 1965 E. E. BALDWIN VENTURI TYPE SAFETY DEVICE 3 Sheets-Sheet 1 Filed NOV. 26, 1962 E ual E3 Baldwin IN VENTOR.

May 11, 1965 E. E. BALDWIN I V VENTURI TYPE SAFETY DEVICE Filed Nov. 26, 1962 s Sheets-Sheet 2 May 11, 1965 E. E. BALDWIN VENTURI TYPE SAFETY DEVICE 3 Sheets-Sheet 3 Fil ed Nov. 26, 1962 E00! E Baldwin INVENTOR. BY @av MM r 3,182,680 [Ce Patented May 11, 1365 3,182,680 VENTURI TYPE SAFETY DEVICE Eual 'E. Baldwin, P.0. Box 691, Alice, Tex. Filed Nov. 26, 1962, Ser. No. 240,034 Claims. (Cl. 137-351) This invention comprises a novel and useful venturi type safety device and more particularly pertains to a gas mixing and diluting device for rendering innocuous vapors from volatile liquids and especially vapors from volatile liquid tanks.

In the storage, dispensing and handling of many volatile liquids, the vapors arising therefrom are dangerous or harmful in various manners. In addition to their constituting a very serious fire hazard in the case of combustible liquid vapors, they may otherwise constitute a menace to health in the case of nocuous vapors from various chemicals. It is the primary purpose of this invention to provide an apparatus which will effectively render such vapors innocuous prior to their discharge into the atmosphere or to other destinations by diluting such vapors by mixing therewith air or other gases in a highly efiicient and effective manner.

A further object of the invention is to provide a safety device especially adapted for incorporation into a tank truck structure which will substantially completely remove any hazard to health or safety arising from the handling of liquid cargoes containing or producing dangerous volatile vapors.

A further object of the invention is to provide a device in accordance with the preceding object which shall be especially useful for removing and rendering innocuous the fumes or vapors arising from volatile liquids of the tank truck particularly during loading or unloading of the tank for various purposes.

A still further important object of the invention is to provide a device in accordance with the preceding object which will utilize a venturi action in mixing a diluting medium such as air with noxious vapors released from the tank or container during loading or unloading thereof whereby such vapors may be rendered innocuous and may then be safely discharged into the atmosphere.

A still further important object of the invention'is to provide an apparatus in conformity with the preceding objects wherein the mixing and diluting device shall be mounted upon a truck and shall be operated from the power plant of the truck and shall produce a forced discharge and mixing of the volatile vapors with the diluting gas such as air in the mixing device.

An additional important object of the invention is to provide a device in accordance with the preceding objects which shall include provision for separating any condensate from the volatile vapors and discharging the condensation separately so that only gases pass through the mixing and diluting device.

Yet another purpose of the invention is to provide an apparatus in accordance with the preceding object which shall permit a diverse and varied control of the flow of gases with respect to the mixing device, the storage tank of the truck and the atmosphere.

And a final important specific object of the invention is to provide a safety mixing device in which the forced discharge of noxious vapors thereinto serves to draw in a sufficient quantity of diluting air or other gas to render the vapors innocuous during their passage through the device.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a fragmentary view in side elevation of a portion of a conventional tank truck showing the manner in which the safety device of this invention is applied thereto;

FIGURE 2 is a view in vertical transverse section taken substantially upon the plane indicated by the section line 2--2 of FIGURE 1 and showing certain details of the arrangement of the safety device;

FIGURE 3 is a view in vertical longitudinal section taken upon an enlarged scale through the venturi mixing element of the device;

FIGURE 4 is a view in top plan of the device of FIG- URE 3;

FIGURE 5 is a detail view in horizontal section taken substantially upon the plane indicated by the section line 55 of FIGURE 3; and

FIGURE 6 is a diagrammatic view illustrating the flow of vapors in accordance with this invention.

Referring first to FIGURE 1 of the accompanying drawings, the numeral 10 indicates generally any suitable tank truck including a storage tank or container 12 thereon and which container is mounted upon the chassis of the truck. The container has a conventional hatch 14 by means of which liquid and/or vapors may be discharged into the truck and from which vapors may be withdrawn during either the loading or unloading operation of the tank.

Referring now more particularly to FIGURES 1 and 2, it is to be noted that the safety device for rendering innocuous dangerous vapors or fumes from the tank 12 during either loading or unloading of the latter is compactly mounted upon the chassis of the truck between the truck cab 16 and the tank 12. The safety device includes a venturi gas mixing unit indicated generally by the numeral 20, a condensate settling tank 22, a multiple control valve 24, a gas circulating pump 26 together with suitable conduits and connections therebetween.

Referring now more specifically to FIGURE 3 it will be observed that the venturi type mixing device comprises a vertically elongated hollow body consisting preferably of a cylindrical central portion 28 from whose upper open end rises an upwardly divergent conical funnel-like hood or discharge member 30 communicating with the atmosphere and which serves as an expansion chamber at the discharge end of the device.

At its lower end, the member 28 has a conical downwardly divergent sleeve 32 having an inner liner 34 of similar tapered configuration. Preferably this liner at its lower end is integral with the member 32, being conneoted thereto by an annular bottom wall 36. The upper edge 38 of the inner liner terminates in closely spaced relation to the lower edge of the cylindrical member 28 and its junction with the upper end of the conical member 32 to provide thereby an annular orifice 40 therebetween which opens into the lower end of the member 28. The interior of the member 28 thus constitutes a mixing chamber 42 for mixing a diluting medium such as air with the dangerous or noxious vapors from any suitable source such as the storage tank 12 of the tank truck. Preferably, the annular nozzle 38 is so arranged that the fluid discharged therefrom is directed upwardly and inwardly of i the mixing chamber 42 from adjacent the walls thereof as indicated by the arrows in FIGURE 3.

It will be noted that there is thus defined a jacket or chamber lying between the inner wall of the member 32 and the wall of the lining 34. An inlet conduit 44 communicates with the annular lower portion of this jacket or chamber and serves to introduce thereinto under pressure the vapors to be diluted and rendered innocuous by the operation of this device.

It will be noted that the diametrically enlarged open lower end 46 of the device constitutes an inner opening through which air or other diluting medium may enter into the mixing chamber 42. As indicated by the arrows in FIGURE 3, there is thus provided a passage extending .entirely through the device 20 with the diluting medium being introduced into one end of the passage and the diluted and innocuous mixture of vapor or fumes with the air being discharged from the other end 30 thereof.

As so far described, it will now be understood that the members 32, 34 and their orifice d constitute a venturi for the flow of air and this flow is caused and stimulated by the pressure discharge of gases through the annular orifice 40 into the mixing chamber 42. The velocity of flow of these gases but at a relatively low volume of flow produces a relatively high volume of flow of air or other diluting gas but at a relatively low velocity. Thus, by properly proportioning and controlling the rate of flow through the physical characteristics of the orifice and the passage areas, or by the use of other control means as may be desired, it is possible to obtain any desired proportioning of the air or other diluting gas with the noxious vapors and thus obtain an innocuous or harmless mixture for discharge from the member 3b to the atmosphere.

Referring now especially to FIGURES 1 and 2 and with some reference to FIGURE 6, it will be seen that there is provided a pipe or conduit 50 having one end communicating with the tank 12 through the discharge hatch 14 and having its other end communicating with the lower portion of the settling tank or condensate tank 22.

From the upper end of the settling tank 22 there is connected a further pipe or conduit 52 by means of which vapors from the upper end of the tank 22 are delivered to the multiple valve unit 24 as indicated by the arrows in these figures. The valve 24 is preferably manually operated and adjusted to a number of different positions to perform different functions as set forth in detail hereinafter. The discharge side of the multiple valve unit 24 is connected to a T-fitting 54 to which the inlet conduit 44- is connected by which the vapors are delivered into the venturi mixing device. Also connected to the T-fitting by a conduit 56 is a manually operated control valve 58 which controls delivery to a mufller 6%) having an exhaust pipe 62. The arrangement is such that by proper manipulation of the valve 24, the noxious vapors under pressure may be selectively delivered either to the inlet conduit 44 and thus into the mixing device, for dilution before being discharged to the atmosphere, or may, when the valve 58 is opened be alternatively delivered to the muffler 60 for direct discharge to the atmosphere. This latter course would be employed when the vapors are considered to be sufficiently innocuous in themselves to require no further dilution.

The settling condensate tank 22 may be of any desired character and inasmuch as the construction and operation of tanks for the settling and separation of gases and liquids is well known, a further description of the same is thought to be unnecessary. From the lower end of this tank there is provided a discharge conduit 64 having a manually operated control valve 66 by means of which the liquid condensate collecting in the tank 22 may be from time to time discharged through the drain pipe 68 thereof. This arrangement prevents the passage of the liquid condensate through the mixing chamber, so that the latter is required only to handle gases and thus has greatly increased efficiency of operation.

At this point it should be understood that the pump 26 of any desired type is preferably of a centrifugal blower type adapted to handle large volumes of gases. This pump is preferably connected to the power plant of the truck, now shown, as by a driving connection indicated generally by the numeral 70 in FIGURES 1 and 2. Thus,

through the operation of suitable controls, the blower 26 may be placed .into operation and will serve to induce a positive flow of gases through the various passages and conduits of this system. Inasmuch as the details of a blower for gases is Well known and the particular structure of the blower forms no part of the invention set forth in the claims hereinafter, a further description of this portion of the apparatus is deemed to be unnecessary.

Referring now especially to FIGURES 2 and 6, it will be observed that the pump 26 is connected to the multiple valve unit 24 by means of a pair of pipes as at 72 and 74. The arrangement is such that the pump causes a flow as indicated by the arrows in FIGURE 6 so that the vapors supplied to the multiple valve unit 24 through the conduit 52 pass through this valve unit and through the pipe 74 into the pump 26 being discharged by the pipe 72 to the multiple valve unit 24 and from thence to the T-fitting 54. From the latter the vapors are selectively discharged into the mixing device 20 or to the muffier to the at mosphere. The valve may then be manipulated to reverse the direction of flow through the pipes 72 and 74 and thus through the associated pipe system was to force fresh air directly into the tank 12 to purge the latter if desired, to assist in discharging the liquid content of the tank if desired. The device thus enables the pump to deliver gas in either direction and perform either function of supplying scavaging or pressure air into the tank 12 or of providing a pressure discharge of the tank means into the mixing device 20 with the suction being applied to the conduits 52 and St to the tank to assist in withdrawing fumes therefrom.

Indicated generally by the numeral 76 in FIGURE 2 is a portion of the chassis of the tank truck upon which a suitable supporting structure serves to mount and support the various elements of this apparatus.

There is thus provided a compact device by being adapted for use on conventional tank trucks to perform the advantages now above enumerated.

As set forth hereinbefore in the accompanying drawings there is disclosed specifically the application of this invention to a tank truck. It will be appreciated, however, that the safety device may be utilized with other containers or tanks whether mobile or stationary or even to receive harmful or noxious gases from any source in order to render them innocuous and dilute them by the admission and mixture therewith of air or other diluting agent. The device effectively utilizes the pressure and velocity of flow of the noxious vapors or gases in order to effect the admixing therewith of a diluting gas such as air.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

' What is claimed as new is as follows:

1. A tank truck including a chassis and a container thereon for storing a volatile liquid having dangerous vapors, a safety device for rending said vapors innocuous for discharge to the atmosphere, said safety device comprising a substantially vertically elongated body fixedly mounted on said truck and having therethrough an unobstructed passage open at both the top and bottom of said body and with a mixing chamber therein, the open lower end of said passage comprising an air inlet means for said mixing chamber, vapor inlet means at the lower end of said passage for said mixing chamber, a pump mounted upon said truck and having an inlet and exhaust, a vapor inlet conduit connecting said pump inlet with the upper portion of said tank for Withdrawingvapor therefrom, a vapor delivery conduit connecting said pump outlet to said vapor inlet means and elfecting a high velocity flow of vapor through said vapor inlet means, said vapor and air inlet means including concentric openings into said mixing chamber with said vapor inlet means opening surrounding said air inlet means opening, whereby said vapor and air flows through said mixing chamber are so proportional by the relative areas of said concentric openings as to dilute said vapors and produce an innocuous mixture of air and vapor 2. The combination of claim 1 including a vertically extending condensate chamber interposed in said vapor inlet conduit having its lower end communicating with said tank and its upper end communicating with said pump inlet, a condensate drain means connected to the bottom portion of said condensate chamber.

3. The combination of claim 1 wherein said truck includes a cab spaced from said tank, said safety device being disposed in the space between said cab and tank, said pump being driven by the truck power plant.

4. The combination of claim 1 including a control valve interposed in said vapor delivery conduit and operable References Cited by the Examiner UNITED STATES PATENTS 1,567,313 12/25 Wilson et al. 55-186 X 1,587,864 6/26 Sargent 137-351 X 1,942,048 1/34 Clark 230-95 2,120,563 6/38 Lamb.

2,361,861 10/44 Masowich 230-95 M. CARY NELSON, Primary Examiner. 

1. A TANK TRUCK INCLUDING A CHASSIS AND A CONTAINER THEREON FOR STORING A VOLATILE LIQUID HAVING DANGEROUS VAPORS, A SAFETY DEVICE FOR RENDING SAID VAPOR INNOCUOUS FOR DISCHARGE TO THE ATMOSPHERE, SAID SAFETY DEVICE COMPRISING A SUBSTANTIALLY VERTICALLY ELONGATED BOBY FIXEDLY MOUNTED ON SAID TRUCK AND HAVING THERETHROUGH AN UNOBSTRUCTED PASSAGE OPEN AT BOTH THE TOP AND BOTTOM OF SAID BODY AND WITH A MIXING CHAMBER THEREIN, THE OPEN LOWER END OF SAID PASSAGE COMPRISING AN AIR INLET MEANS FOR SAID MIXING CHAMBER, VAPOR INLET MEANS AT THE LOWER END OF SAID PASSAGE FOR SAID MIXING CHAMBER, A PUMP MOUNTED UPON SAID TRUCK AND HAVING AN INLET AND EXHAUST, A VAPOR INLET CONDUIT CONNECTING SAID PUMP INLET WITH THE UPPER PORTION OF SAID TANK FOR WITHDRAWING VAPOR THEREFROM, A VAPOR DELIVERY CONDUIT CONNECTING SAID PUMP OUTLET TO SAID VAPOR INLET MEANS AND EFFECTING A HIGH VELOCITY FLOW OF VAPOR THROUGH SAID VAPOR INLET MEANS, SAID VAPOR AND AIR INLET MEANS INCLUDING CONCENTRIC OPENINGS INTO SAID MIXING CHAMBER WITH SAID VAPOR INLET MEANS OPENING SURROUDNING SAID AIR INLET MEANS OPENING, WHEREBY SAID VAPOR AND AIR FLOWS THROUGH SAID MIXING CHAMBER ARE SO PROPORTIONAL BY THE RELATIVE AREAS OF SAID CONCENTRIC OPENINGS AS TO DILUTE SAID VAPORS AND PRODUCE AN INNOCUOUS MIXTURE OF AIR AND VAPOR. 